On Wed, Aug 11, 2010 at 12:32 AM, Matt Fleming <matt@xxxxxxxxxxxxxxxxx> wrote:
> On Mon, Aug 09, 2010 at 08:33:16PM +0800, zhangfei gao wrote:
>>
>> Thanks for your careful review, in our platform, we use max/min for
>> the max_div, so miss this modification :(
>> Update the patch, help review again.
>
> What do you mean? Where does max/min come from? It would definitely
> be best if everybody uses the same code to calculate max_div. Have
> you tested the max_div changes? Are you now using this patch on
> your platform or are you still maintaining a patch to do it a
> different way?
>
> If you've got a separate patch and it does this things better
> than the way we currently do them, get it upstream! :-)
>
Hi, Matt
Thanks for your reminder, totally agree with you.
We also use this patch in our platform, and find another issue, div
should +=2 instead of *=2.
- for (div = 1;div < 256;div *= 2) {
+ for (div = 1;div < max_div;div += 2) {
Update patch, help review.
>From 517077ffae66dd12c409b7c6b41a7014db66a3cc Mon Sep 17 00:00:00 2001
From: Zhangfei Gao <zgao6@xxxxxxxxxxx>
Date: Fri, 6 Aug 2010 07:10:01 +0800
Subject: [PATCH] sdhc: support 10-bit divided clock Mode
Signed-off-by: Zhangfei Gao <zgao6@xxxxxxxxxxx>
Reviewed-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 14 ++++++++++----
drivers/mmc/host/sdhci.h | 4 ++++
2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c6d1bd8..b2d5e5e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -978,7 +978,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
- int div;
+ int div, max_div;
u16 clk;
unsigned long timeout;
@@ -996,13 +996,19 @@ static void sdhci_set_clock(struct sdhci_host
*host, unsigned int clock)
if (clock == 0)
goto out;
- for (div = 1;div < 256;div *= 2) {
+ if (host->version >= SDHCI_SPEC_300)
+ max_div = 2046;
+ else
+ max_div = 256;
+
+ for (div = 1;div < max_div;div += 2) {
if ((host->max_clk / div) <= clock)
break;
}
div >>= 1;
- clk = div << SDHCI_DIVIDER_SHIFT;
+ clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
+ clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIVIDER_SHIFT) <<
SDHCI_DIVIDER_SHIFT_HI;
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
@@ -1681,7 +1687,7 @@ int sdhci_add_host(struct sdhci_host *host)
host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
host->version = (host->version & SDHCI_SPEC_VER_MASK)
>> SDHCI_SPEC_VER_SHIFT;
- if (host->version > SDHCI_SPEC_200) {
+ if (host->version > SDHCI_SPEC_300) {
printk(KERN_ERR "%s: Unknown controller version (%d). "
"You may experience problems.\n", mmc_hostname(mmc),
host->version);
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index c846813..7c09b4f 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -85,6 +85,9 @@
#define SDHCI_CLOCK_CONTROL 0x2C
#define SDHCI_DIVIDER_SHIFT 8
+#define SDHCI_DIVIDER_SHIFT_HI 6
+#define SDHCI_DIV_MASK 0xFF
+#define SDHCI_DIV_HI_MASK 0x300
#define SDHCI_CLOCK_CARD_EN 0x0004
#define SDHCI_CLOCK_INT_STABLE 0x0002
#define SDHCI_CLOCK_INT_EN 0x0001
@@ -177,6 +180,7 @@
#define SDHCI_SPEC_VER_SHIFT 0
#define SDHCI_SPEC_100 0
#define SDHCI_SPEC_200 1
+#define SDHCI_SPEC_300 2
struct sdhci_ops;
--
1.6.0.4
Attachment:
0001-sdhc-support-10-bit-divided-clock-Mode.patch
Description: Binary data
